Nano-Boosters & Nano-Labels

ChromoTek's Nano-Boosters & Nano-Labels are very small, highly specific binding proteins, also called Nanobodies and VHHs. These are derived from single-domain alpaca antibody fragments that are covalently coupled to bright and stable fluorescent dyes. Nano-Boosters, e.g. GFP- and RFP-Booster, boost/enhance the signal of fluorescent proteins; Nano-Labels, e.g. Vimentin- and Histone-Label, fluorescently label proteins.


  • Higher image resolution
  • Excellent performance in IF and super-resolution microscopy
  • Stabilization, enhancement and reactivation of fluorescent signals
  • Less than 2nm epitope-label displacement minimizes linkage error
  • Recombinant single domain antibody fragment from camelid

Nano-Boosters & Nano-Labels (also termed fluorophore conjugated nanobody or VHH) are much smaller compared to conventional primary plus secondary antibodies (IgG complex). Due to their small size, VHHs are particular suitable for effective labelling with minimal fluorophore displacement for super-resolution microscopy. For relative comparison of the sizes of both affinity reagents see picture (right).

Super resolution microscopy

STED: IF of Spot-tagged Actin-Chromobody with Spot-Label Atto594 bivalent (1:1,000). Gated STED images were acquired with a Leica TCS SP8 STED 3X microscope with pulsed White Light Laser excitation at 590 nm and pulsed depletion with a 775 nm laser. Objective: 100x Oil STED White, NA: 1.4. Pixel size: 21 x 21 nm; z-Step size of z-Stacks: 0.16 µm. Images were deconvolved with Huygens Professional (SVI). STED images were recorded at the Core Facility Bioimaging at the Biomedical Center, LMU Munich.



Tissue penetration rate
The comparison of conventional anti-GFP antibody and GFP-Booster shows the superior tissue penetration rate of GFP-Booster. Fluorescent images of transgenic mouse tissue expressing Cx3Cr1-EGFP. EGFP signal was enhanced either with conventional anti-GFP antibody conjugated to Alexa 647 (top image) or with the GFP-Booster_Atto647N (bottom image).

Central nervous system of a 3-day-old Drosophila larvae. GFP-Booster_ATTO488 was used to enhance the signal of dopamine neurons expressing GFP. (Image kindly provided by Kayvan Forouhesh Tehrani, the Kner Lab, University of Georgia; the Drosophila sample was supplied by the Shen lab, University of Georgia, Athens.)

Fluorescent proteins (FPs) are powerful tools to study protein localization and dynamics in
living cells. However, genetically encoded FPs have a number of disadvantages compared to chemical dyes:

  • Signal intensities of fixed samples from cells expressing FP fusion at physiological expression levels are usually very low.
  • Both photostability and quantum efficiency of FPs are generally not sufficient for
    super-resolution microscopy (e.g. 3D-SIM, STED or STORM/ PALM).
  • Many cell biological methods such as HCl treatment for BrdU-detection, the
    EdU-Click-iT™ treatment or heat denaturation for FiSH lead to disruption of the FP signal.

Learn more about our technology

In these cases, our Boosters will help you to get better images from your existing GFP/RFP expression constructs:

  • conventional immunofluorescence (IF)
  • histological stainings (IHC)
  • cell lines
  • tissue sections
  • fruit fly embryos
  • wide-field epifluorescence microscopy
  • confocal microscopy
  • super-resolution microscopy
    (e.g. 3D-SIM, PALM, STED, STORM)
  • VHHs do not cluster their epitopes
  • Superior accessibility and labelling of epitopes in crowded cellular environments
  • Atto and Abberior fluorophores conjugated to Nano-Boosters
  • Consistent and reliable performance due to recombinant production

Find the right Nano-Booster/ Nano-Label:

For immunofluorescence of
GFP fusion proteins

For immunofluorescence of
vimentin filaments


For immunofluorescence microscopy
and Western Blot

For immunofluorescence of
RFP fusion proteins

For immunostaining of
of chromatin